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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 271 records · Page 15Linked to original sources

Synergistic effect of methionine-depleting total parenteral nutrition with 5-fluorouracil on human gastric cancer: a randomized, prospective clinical trial.

Methionine-depleting total parenteral nutrition (Met-depleting TPN), infusing AO-90 amino acid solution (lacking both L-methionine and L-cysteine) as a sole nitrogen source, showed synergistic effects with 5-fluorouracil (5-FU) in tumor-bearing rats and in clinical trials with gastrointestinal tract cancers. In this study, the effect of Met-depleting TPN with 5-FU upon thymidylate synthase (TS) activity was examined, and the histological effect of this treatment on human gastric cancer was evaluated. Fourteen preoperative advanced gastric cancer patients were divided randomly into two groups. Seven cases were given Met-depleting TPN for 7 days before surgery with continuous intravenous administration of 5-FU (500 mg/body per day; total 4.0 g/body) (AO-90 group). The other 7 received conventional L-methionine-containing TPN with 5-FU (control group). All patients underwent gastrectomy without complications due to these treatments. Resected materials were examined for TS kinetics, and the anti-cancer effect was also assessed histopathologically. The specimens in the AO-90 group showed marked degeneration of cancer, while almost no effect was seen in the control group. The free TS activity of carcinoma tissue in the AO-90 group was decreased and the TS inhibition rate was increased in comparison with the control group (P = 0.0165 and P = 0.0243, respectively). Met-depleting TPN appears to play a role as a biomodulator of 5-FU in human gastric cancer.

Aged↗

[Serological diagnosis for human parvovirus B19 infection by an enzyme immunoassay kit with recombinant antigens synthesized in a baculovirus expression system].

Propagation of human parvovirus B19 (B19) in cell cultures are not applicable to the source of viral antigens for serological assays at present. Enzyme immunoassay (EIA) kits with recombinant B19 capsids by E. coli or baculovirus expression system have been developed. We tested serum samples from the patients with erythema infectiosum and aplastic crisis by EIA kit with recombinant antigens synthesized in a baculovirus expression system (Denka Seiken Co., Tokyo, Japan). The antigens used in the kit are self-assembled recombinants containing both VP-1 and VP-2 with the same proportion as found in native B19 capsids. B19 IgM is detected by antibody capture methods and IgG by indirect methods. All of the samples were positive for B19 DNA by nested PCR. Thirty-six (97%) of the 37 patients with erythema infectiosum and all (100%) of the 4 patients with aplastic crisis were positive for B19 IgM. The EIA kit with recombinant antigens synthesized in a baculovirus expression system has proved to be reliable and useful for the diagnosis of B19 infection.

Antibodies, Viral↗

[Seroepidemiology of human parvovirus B19 using recombinant VP1 + VP2 particle antigen].

Antibody prevalence to B19 virus in Japan was previously reported with 1973 and 1984 serum collections. Since then we have had two big epidemics of erythema infectiosum in Japan: 1986-87 and 1991-92. In an attempt to estimate how much those epidemics have affected seroprevalence to B19 virus infection, we studied seroepidemiology in three separate areas using a newly developed ELISA system consisting of recombinant VP1 + VP2 particle antigen. Total of 900 sera obtained in 1993 from healthy individuals living in northern, central and southwest parts of Japan were assayed for the presence of anti B19 IgG antibody. In the first, the new assay system was compared with our conventional assay system in which native B19 virus particles were used as antigen. Of 220 serum samples tested, 212 (96.4%) gave same results in both assays. Remaining 8 samples which gave variable results were those of near cut off values. We concluded that this new ELISA system can be recommended for seroepidemiological use. Antibody prevalence rates were 10% (0-4 y), 54% (5-9 y), 59% (10-14 y), 46% (15-19 Y), 38% (20-29 y), 48% (30-39 y), 64% (40-49y) and 76% (50 y-). No gender difference was observed. Comparison of antibody prevalences in 1973, 1984 and 1993 suggested that approximately 10% (about 8 million people) of the total population under 40 years of age acquired immunity to B19 virus during one epidemic period.

Adolescent↗

Purification and characterization of angiotensin I-converting enzyme inhibitors from sour milk.

The inhibitory activity of angiotensin I-converting enzyme in milk increased during fermentation with the Calpis sour milk starter containing Lactobacillus helveticus and Saccharomyces cerevisiae. Two kinds of peptides inhibitory to angiotensin I-converting enzyme were purified from the sour milk by using four-step HPLC. The amino acid sequences of these inhibitors were identified as Val-Pro-Pro and Ile-Pro-Pro. The concentrations of peptides providing 50% inhibition of angiotensin I-converting enzyme were 9 and 5 microM, respectively. Most of the inhibitory activity in sour milk was attributed to these two peptides.

Amino Acid Sequence↗

[Histological effect and prognosis after preoperative chemotherapy in esophageal cancer].

Preoperative chemotherapy for esophageal cancer was performed and the toxic effects, post-operative complications, histological effects and survival time were evaluated. Toxic effects and post-operative complications were rare. The histological effect was evaluated according to the Guidelines for Clinical and pathologic studies on carcinoma of the esophagus by the Japanese Society for Esophageal Disease. A histological effect of more than Grade II was seen from 25 to 42.1%. A significant difference was seen in the Kaplan-Meier survival curves between the response group and the no response group (p < 0.05). If we perform preoperative chemotherapy for esophageal cancer only to responsive cases determined by chemosensitivity tests, the prognosis of advanced esophageal cancer may be improved.

Adult↗

[A case of Addison's disease complicated by lung carcinoma treated with surgical resection--a case report].

Surgery was successful in a 72-year-old man with Addison's disease complicated by right lower lobe carcinoma of the lung. The patient had been diagnosed Addison's disease 25 years earlier and had been treated with cortisone acetate 25 mg every morning. A tumor shadow was found in the right lower lobe of the lung on chest X-ray. Squamous cell carcinoma was diagnosed by cytological examination. Right lower lobectomy with partial resection of the right diaphragma and lymph-node dissection were performed. The bronchial stump was closed using Sweet's method and covered with a pericardial fat pad. The intra- and post-operative course was uneventful with intravenous administration of adequate doses of hydrocortisone. The patient has been free from the carcinoma for two years.

Addison Disease↗

Adenovirus surveillance, 1982-1993, Japan. A report of the National Epidemiological Surveillance of Infectious Agents in Japan.

The Infectious Agents Surveillance Center, the National Institute of Health, Japan, received 17,265 reports from 1982 to 1993 on cases from whom adenovirus was isolated or detected; 85% from 57 public health institutes and the other 15% from two national hospitals and two commercial diagnostic laboratories. The followings were found. Three major diseases caused by adenovirus were upper respiratory tract infection, gastroenteritis, and conjunctivitis. Patients of upper respiratory tract infection numbered 6,837 (40% of all patients due to adenovirus), the identified serotypes being in order of frequency types 3, 2, 1, and 5. Those of gastroenteritis numbered 1,636 (9.5%). From 40% of the gastroenteritis patients, adenovirus was detected by electron microscopy or immunochemical methods without cultivation. From the remaining 60%, virus was isolated in tissue culture; the serotypes of the isolates resembled those causing upper respiratory tract infection. Patients of conjunctivitis numbered 3,437 (20%), the frequency being in order of types 3, 4, 8, 37, and 19. Conjunctivitis due to types 3 and 4 prevailed every summer; type 3 was isolated often from children with pharyngo-conjunctival fever and the other four types were mostly from adults with epidemic keratoconjunctivitis. Type 3 had a unique feature not seen in other types: it was most frequently isolated, causing upper respiratory tract infection, gastroenteritis, conjunctivitis, and pharyngo-conjunctival fever. Reports on isolation of type 7, which has been reported to cause severe pneumonia in many other countries, were as few as 28 (0.2%).

Adenoviridae Infections↗

The concept of "template" assisted electronic medical record.

A new design for an electronic medical record with flexible template generation was developed. The "template" in this paper refers to one of the tools that calls a user's attention to entering the data items for each problem or to ordering tests when they are due. The template shows the patient's previous data and guides physicians to record the consistent description. Two kinds of medical data dictionaries are prepared. Data representations of signs, symptoms, laboratory tests, and other examinations are defined in the check items dictionary. The problem dictionary contains the possible patient problems with relation to check items and other kinds of related subjects. This system provides Problem Oriented Medical Record (POMR) and the graphical presentation of various patient data. The system was designed to establish a constant and integrated medical record.

Artificial Intelligence↗

Computer assisted instruction on multimedia environment for patients.

Computer Assisted Instruction (CAI) is a valuable tool that not only encourages patients, but also provides medical information and the motivation for self management. We developed three modules within a multimedia environment for patients with diabetes or bronchial asthma; positive results were obtained. By using CAI, a reduction in the nurses' workload is achieved along with patients gaining profound and standardized knowledge. We also found some substantial characteristics in the patients' learning behavior and the value of "active learning" in CAI.

Asthma↗

Implementation and evaluation of computerized patient management problems.

We developed and implemented computerized patient management problems (CPMP) for medical school education as a simulation of case management and evaluated its efficacy in the School of Medicine at Chiba University. PMP was first developed in the USA; it was used for examinations by the board of American College of Physicians and then introduced to Japan for examination purposes. This test is a practical clinical test for decision making in various medical situations. PMP is, however, a kind of case simulation from a doctor's point of view; it is also a sophisticated tool in training medical students. PMP had many disadvantages in the past, but by computerizing PMP, we solved many problems. We developed the CPMP system for bedside teaching and evaluated its efficiency in terms of education by giving the same test twice and analyzing a survey.

Audiovisual Aids↗

Immunosuppression to cardiac allografts and soluble antigens by anti-vascular cellular adhesion molecule-1 and anti-very late antigen-4 monoclonal antibodies.

Effective activation of T cells in immune responses depends on two signals, one from the CD3/TCR complex and another from accessory cell surface proteins. Very late Ag-4 (VLA-4) can exert a costimulatory function upon binding with vascular cellular adhesion molecule-1 (VCAM-1). We investigated the effects of mAbs against VCAM-1 and VLA-4 on cardiac allograft survival and humoral response to soluble Ags. BALB/c hearts were transplanted into C3H/He recipients. mAbs (100 micrograms/day) were administered i.p. for the first 6 days. Graft survival in mice treated with M/K-2 (anti-VCAM-1; median survival: 20 days, n = 6) and those treated with PS/2 (anti-VLA-4; 30 days, n = 6) was greater than that in control mice (8 days, n = 7). Eight of 18 mice treated with both M/K-2 and PS/2 accepted the grafts over 65 days, and five of them accepted the grafts over 100 days. Allografts treated with the two mAbs showed scattered infiltration of leukocytes without evidence of active rejection at 65 days. Mice with long-surviving cardiac grafts were challenged with skin grafts from donor and third-party (C57BL/6) strains. Survival of the donor-type skin was significantly greater than that of the third-party skin. One mouse specifically accepted the donor-type skin indefinitely (> 150 days). FACS analysis of splenocytes at 55 days after transplantation showed complete recovery of VLA-4 expression from a down-regulation observed at day 7. In addition, mice immunized with heat-aggregated human gamma-globulin did not produce specific Ab, even after boost immunization, if PS/2 was administered at the time of the first immunization. This unresponsiveness to xenogeneic protein lasted for more than 50 days. These results indicate that in vivo administration of anti-VCAM-1 and anti-VLA-4 mAbs induces specific immunosuppression to cardiac allografts and soluble Ags.

Animals↗

Circadian rhythms of adenosine triphosphate contents in the suprachiasmatic nucleus, anterior hypothalamic area and caudate putamen of the rat--negative correlation with electrical activity.

Contents of adenosine triphosphate (ATP) in the suprachiasmatic nucleus (SCN), anterior hypothalamic area (AH) and caudate putamen (CPu) were determined every 4 h in rats kept under constant dark conditions. All tested regions of the brain exhibited circadian rhythms in ATP content. Among these, the amplitude of the rhythm was largest in the SCN. Peaks of the ATP content were observed at circadian time 18 in the SCN, 6 in the AH and 10 in the CPu. In view of the observation that at around these peak times electrical or glucose uptake activity of each brain region was lowest, the present result suggests that ATP content is negatively correlated with electrical or glucose uptake activity.

Adenosine Triphosphate↗

Origin of a T cell clone with a mismatched combination of MHC restriction and coreceptor expression.

Although the existence of a large number of CD8+ class II MHC-specific CTLs had long been noticed, the origin of such T cells with a discordant combination of specificity and phenotype has been a mystery in the positive selection model. Recent reports suggesting the independency of the positive selection of T cells from coreceptor-mediated signals raised a possibility that they might be the progeny of putative transitional, mismatched, single-positive cells appearing before positive selection as proposed in the stochastic/selective model. By developing transgenic mice carrying TCR alpha and beta chain genes of a CD8+ class II MHC Ag-specific allogeneic CTL clone QM11, the origin of such T cells with mismatched TCR specificity and coreceptor expression was studied. The results indicate that QM11 belongs to a conventional CD8+ T cell population whose maturation is dependent on a class I (or class I-like) MHC product. Consequently, the reactivity of QM11 to I-Ak can be considered to be an accidental cross-reaction.

Animals↗

Ranking Japan's life science research.

Some surprising facts about the most productive institutions emerge when Japanese life-science research is subject to a novel type of assessment.

Academies and Institutes↗